1. Field of the Invention
The present invention relates to a motor actuator structured such that an actuator case is formed by a motor case and a gear case, a motor and a gear portion are arranged in an inner side of the actuator case, a rotation of the motor is decelerated by the gear portion, and the decelerated motor rotation is output to an external portion via an output gear, and the motor actuator mentioned above is independently formed and is attached to various equipment. Accordingly, a rotating member provided in the various equipment is rotationally controlled by the motor of the motor actuator. Further, the present invention relates to a throttle body controlling an amount of air flowing for an engine, and more particularly to a tandem type throttle body in which a main throttle valve mechanically operated by an accelerator so as to be opened and closed is arranged within an intake passage provided so as to pass through the throttle body, and an auxiliary throttle valve electrically operated by a motor so as to be opened and closed is arranged within the intake passage in an upstream side from the main throttle valve.
2. Description of the Conventional Art
A first example of a conventional motor actuator is shown in FIG. 4. Reference numeral 30 denotes a motor case in which a motor M is arranged so as to be accommodated in an inner portion. A motor accommodating concave portion 30b is provided in a concave manner toward a right open end 30a in the drawing. Further, the motor M constituted by a step motor or the like provided with an output shaft Ma is arranged so as to be inserted in to the motor accommodating concave portion 30b. Reference numeral 31 denotes a gear case in which a gear portion G is arranged so as to be accommodated in an inner portion. A gear accommodating concave portion 31b is provided in a concave manner toward a left open end 31a in the drawing. Further, the open end 30a of the motor case 30 is brought into contact with the open end 31a of the gear case 31, whereby the actuator case K is formed. Accordingly, the motor and the gear portion G are arranged so as to be accommodated in an inner portion of the actuator K. Further, the gear portion is constituted by a motor gear G1, an intermediate gear G2 rotatably borne to the support shaft 32, and an output gear G3 in which a rotation transmission hole G3a is provided. The motor gear G1 is connected to an output shaft Ma of the motor M and is arranged so as to be engaged with one side of the intermediate gear G2. Further, the other side of the intermediate gear G2 is arranged so as to be engaged with the output gear G3. Further, a mounting boss 33 in which a mounting hole 33a is provided is integrally formed in the open end 30a of the motor case 30, and a mounting boss 34 in which a mounting hole 34a is provided is integrally formed in the open end 31a of the gear case 31. Since the motor case 30 and the gear case 31 are arranged so as to be brought into contact with each other by the mutual open ends 30a and 31a, a mounting boss 36 (formed by the mounting bosses 33 and 34) having a mounting hole 35 (formed by the mounting holes 33a and 34a) is formed in a part of the actuator case K. In accordance with the structure mentioned above, a motor actuator provided with the gear portion G and the motor M is formed in an inner portion of the actuator case K. The motor actuator mentioned above is structured such that an end surface of the boss 36 is arranged so as to be brought into contact with an equipment E, a bolt T is inserted into the mounting hole 35 under the state mentioned above, and the mounting boss 36 is screwed and fixed to the equipment E by the bolt T. On the other hand, one end of a rotating shaft Wa provided in the equipment E is arranged so as to be inserted to the rotation transmission hole G3a of the output gear G3, the insertion is executed by forming a cross sectional shape of the rotation transmission hole G3a in a segmental shape hole and forming a cross sectional shape of the rotating shaft Wa in a segmental shape, and the rotation of the output gear G3 is transmitted to the rotating shaft Wa. In accordance with the structure mentioned above, the rotation of the motor M is decelerated by the gear portion G, the decelerated rotation is transmitted to the rotating shaft Wa via the output gear G3, and it is possible to rotationally control the rotating shaft Wa of the equipment E in correspondence to the rotation of the motor M.
A second example of the conventional motor actuator is shown in FIG. 5. Reference numeral 40 denotes a case in which the motor M and the gear portion G are arranged so as to be accommodated in an inner portion. An accommodating concave portion 40b is provided in a concave manner toward a right open end 40a. Further, the motor M constituted by the step motor or the like provided with the output shaft Ma is arranged and the gear portion G is arranged within the accommodating concave portion 40b. The gear portion G is constituted by the motor gear G1, the intermediate gear G2 rotatably borne to the support shaft 41, and the output gear G3 in which the rotation transmission hole G3a is provided. In the intermediate gear G2 among them, a large-diameter gear G2a and a small-diameter gear G2b are formed in two stages in a longitudinal axial direction of the support shaft 41. Accordingly, the motor gear G1 is engaged with the large-diameter gear G2a of the intermediate gear G2, and the small-diameter gear G2b of the intermediate gear G2 is engaged with the output gear G3. Further, a cover 42 is arranged so as to be brought into contact with the open end 40a of the case 40 and the open end 40a of the case 40 is closed, whereby the actuator case K is formed. Accordingly, the motor and the gear portion G are arranged so as to be accommodated within the closed accommodating space of the actuator K. Further, a mounting boss 43 in which a mounting hole 43a is provided is integrally formed in the open end 40a of the case 40, and a mounting boss 44 in which a mounting hole 44a is provided is integrally formed in the open end 42a of the cover 42. Since the case 40 and the cover 42 are arranged so as to be brought into contact with each other by the mutual open ends 40a and 42a, a mounting boss 46 (formed by the mounting bosses 43 and 44) having a mounting hole 45 (formed by the mounting holes 43a and 44a) is formed in a part of the actuator case K. In accordance with the structure mentioned above, a motor actuator provided with the gear portion G and the motor M is formed in an inner portion of the actuator case K. The motor actuator mentioned above is structured such that an end surface of the mounting boss 46 is arranged so as to be brought into contact with the equipment E, the bolt T is inserted into the mounting hole 45 under the state mentioned above, and the mounting boss 46 is screwed and fixed to the equipment E by the bolt T. On the other hand, one end of the rotating shaft Wa is arranged so as to be inserted into the rotation transmission hole G3a of the output gear G3 in the same manner as mentioned above. In accordance with the structure mentioned above, the rotation of the motor M is decelerated by the gear portion G, the decelerated rotation is transmitted to the rotating shaft Wa via the output gear G3, and it is possible to rotationally control the rotating shaft Wa in correspondence to the rotation of the motor M.
The conventional tandem valve type throttle body is disclosed in Japanese Unexamined Patent Publication No. 2003-83171 filed by the applicant of the present invention. In the tandem valve type throttle body mentioned above, an intake passage is provided so as to pass through the throttle body, and a main throttle valve is attached to a main throttle valve shaft which is rotationally operated mechanically by a vehicle driven, whereby the intake passage is opened and closed. Further, in the intake passage in an upstream side from the main throttle valve, an auxiliary throttle valve is attached to an auxiliary throttle valve shaft which is rotationally operated electrically by a motor, and the intake passage in the upstream side from the main throttle valve is electrically opened and closed by the auxiliary throttle valve. On the other hand, the motor actuator is structured such that the actuator case is formed by the gear case and the motor case, the motor and gear are arranged within the actuator case, the rotation of the motor is decelerated by the gear and the auxiliary throttle valve shaft is rotationally operated by the output gear, whereby the auxiliary throttle valve electrically controls the intake passage in the upstream side from the main throttle valve so as to open and close.